In recent years, a movement has gained traction to replace incandescent light bulbs with lighting fixtures that employ more efficient lighting technologies, as well as to replace relatively efficient fluorescent and high intensity discharge (HID) lighting fixtures with lighting technologies that produce a more pleasing, natural light. One such technology that shows tremendous promise employs light emitting diodes (LEDs) as the light source. Compared with incandescent bulbs, LED-based light fixtures are much more efficient at converting electrical energy into light, are longer lasting, and are also capable of producing light that is very natural. Compared with fluorescent and/or HID lighting, LED-based fixtures are still significantly more efficient and capable of producing light that is much more natural and more capable of accurately rendering colors. As a result, lighting fixtures that employ LED technologies are replacing incandescent, fluorescent, and HID bulbs in residential, commercial, and industrial applications.
LED-based fixtures generally employ relatively complex power supplies and control circuitry, which are collectively referred to as drivers, to convert an AC supply voltage to a DC supply voltage that is used to power the LEDs and the other electronics of the LED-based fixtures. In addition to providing the DC supply voltage, the drivers control how the LEDs are driven in an effort to provide light for general illumination at the appropriate intensity, color, and color temperature. As with most electronics, these drivers often require surge protection circuitry to prevent voltage or current spikes from damaging or destroying the electronics of the driver and/or the associated LEDs.
Metal Oxide Varistors (MOVs) are often used to provide surge protection for LED-based fixtures and other types of electronics. One or more MOVs are generally coupled between the AC supply lines and function to clamp voltage spikes, which are referred to herein as overvoltage events, to an acceptable level. Unfortunately, the MOVs degrade with each successive overvoltage event and ultimately fail after being exposed to a relatively few number of overvoltage events. For example, commonly used MOVs often fail after being subjected to only six to eight overvoltage events. Once the MOV fails, the MOV provides no protection for overvoltage events. As such, there is a need for a way to provide an alert indicative of an MOV being damaged or needing to be replaced prior to the MOV actually failing.